Radio emission from extensive air showers

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Winter residency and site association in the critically endangered North East Atlantic spurdog (Squalus acanthias)

Identification and incorporation of residential behaviour into elasmobranch management plans has the potential to substantially increase their effectiveness by identifying sites where Marine Protected Areas (MPAs) might be used to help conserve species with high migratory potential. There is evidence that spurdog (Squalus acanthias) displays site association in some parts of its global distribution, but this has currently not been shown within the North East Atlantic where it is critically endangered. Here we investigate the movements of electronically tagged spurdog within Loch Etive, a sea loch on the west coast of Scotland. Archival data storage tags (DSTs), that recorded depth and temperature, revealed that mature female spurdog over wintered within the loch, restricting their movements to the upper basin, and remaining either in the loch or the local vicinity for the rest of the year. This finding was supported by evidence for limited movements from conventional mark/recapture data and acoustically tagged individual spurdog. Some of the movements between the loch basins appear to be associated with breeding and parturition events. This high level of site association suggests that spatial protection of the loch would aid the conservation of different age and sex classes of spurdog

A trait-based metric sheds new light on the nature of the body size-depth relationship in the deep sea

Summary 1. Variation within species is an often-overlooked aspect of community ecology, despite the fact that the ontogenetic structure of populations influences processes right up to the ecosystem level. Accounting for traits at the individual level is an important advance in the implementation of trait-based approaches in understanding community structure and function. 2. We incorporate individual- and species-level traits into one succinct assemblage structure metric, fractional size, which is calculated as the length of an individual divided by its potential maximum length. We test the implementation of fractional size in demersal fish assemblages along a depth gradient in the deep sea. We use data from an extensive trawl survey at depths of 300–2030 m on the continental slope of the Rockall Trough, Northeast Atlantic, to compare changes in fractional size structure along an environmental gradient to those seen using traditional taxonomic and trait-based approaches. 3. The relationship between fractional size and depth was particularly strong, with the overall pattern being an increase with depth, implying that individuals move deeper as they grow. Body size increased with depth at the intraspecific and assemblage levels. Fractional size, size structure and species composition all varied among assemblages, and this variation could be explained by the depth that the assemblage occupied. 4. The inclusion of individual-level traits and population fractional size structure adds to our understanding at the assemblage level. Fractional size, or where an individual is in its growth trajectory, appears to be an especially important driver of assemblage change with depth. This has implications for understanding fisheries impacts in the deep sea and how these impacts may propagate across depths

Dependence of the micro-arcsecond metrology (MAM) testbed performance prediction on white light algorithm approach

MAM is a dedicated systems-level testbed that combines the major SIM subsystems including laser metrogy, pointing, and pathlength control. The testbed is configured as a modified Michelson interferometer for the purpose of studying the white-light fringe measurement processes. This paper will compare the performance of various algorithms using the MAM data, and will aid in our recommendation of how the SIM flight system should process the science and guide interferometer data

Using individual tracking data to validate the predictions of species distribution models

The authors would like to thank the College of Life Sciences of Aberdeen University and Marine Scotland Science which funded CP's PhD project. Skate tagging experiments were undertaken as part of Scottish Government project SP004. We thank Ian Burrett for help in catching the fish and the other fishermen and anglers who returned tags. We thank José Manuel Gonzalez-Irusta for extracting and making available the environmental layers used as environmental covariates in the environmental suitability modelling procedure. We also thank Jason Matthiopoulos for insightful suggestions on habitat utilization metrics as well as Stephen C.F. Palmer, and three anonymous reviewers for useful suggestions to improve the clarity and quality of the manuscript.Peer reviewedPostprintPostprintPostprintPostprintPostprin

Deep Sea – Close Kin: A Genetic Approach for Improved Fisheries Management

Deep-sea fish stocks consist of species that live at depths of greater than 400 metres. While being important for EU fisheries, this natural renewable resource is particularly vulnerable to over-fishing, as many deep sea species are slow-growing and commonly of low fecundity. Generally little is known about the biology of deep sea species, and there prevails a substantial lack of scientific data on deep-sea stocks. This constitutes a major impediment to management strategies underpinning sustainable and profitable deep sea fisheries. Europe’s deep-sea fisheries began in the 1970’s and were entirely unregulated. The fleet grew as rewards were high, but many species were rapidly depleted. It was only in 2003 that a management plan was brought into action. While some measures to better protect commercially exploited deep sea fish have been adopted, such as the limitation of fishing effort or total allowable catches, these have been insufficient to allow stocks to recover and there is a general consensus that most deep-water stocks remain below safe biological limits for exploitation. In a recent communication to the Council and the European Parliament, the European Commission has emphasized the need to improve our knowledge on deep sea fish species to move away from the current prevailing unsustainable exploitation. Ideally, this would be the development of a robust and practical approach to estimate the abundance of deep sea species to support stock assessments and reduce the uncertainty about the state and rebuilding rates of commercially exploited deep sea stocks. The current rapid technology development and concurrent steep drop in costs of large-scale genotyping offers major opportunities for fisheries management. This report explores whether the concept of genetic close-kin abundance estimation, recently applied to establish biomass estimates of Southern Bluefin Tuna, can be applied to fisheries management of deep sea fish species.JRC.G.3-Maritime affair

The role and regulation of class IIa HDACs in neuronal antioxidant responses

Reactive oxygen species (ROS) are highly reactive signalling molecules, produced naturally as by-products of oxidative metabolism, which can lead to a state of oxidative stress when in excess. ROS can be cytotoxic to neurons and high levels are linked to many neurodegenerative diseases. Neurons counter excessive ROS in part through transcriptional upregulation of antioxidant enzymes. Class IIa histone deacetylases (HDACs) are transcriptional co-regulators that can either repress or activate gene transcription. They repress MADS box (MEF2) transcription factor mediated gene expression by promoting chromatin compaction and activate forkhead (FOXO) transcription factors through deacetylation. Class IIa HDACs are regulated by signal-dependent nucleocytoplasmic shuttling whereby increased neuronal firing triggers their nuclear export. Whilst these HDACs are linked to both neuroprotection and neurodegeneration, little is known about their activity and regulation under oxidative stress. This thesis aimed to investigate class IIa HDAC regulation under oxidative stress conditions. Oxidative stress was imposed using either diethyl maleate (DEM) to deplete cellular glutathione levels or paraquat which affects the mitochondrial electron transport chain. Work here shows that both HDAC4 and 5 translocate to the nucleus of rat cortical neurons under DEM-induced oxidative stress, whereas paraquat has different effects on HDAC4/5 localisation. Furthermore, HDAC5 showed a dephosphorylation, essential for its nuclear import. Putative FOXO target genes Tpm2 and Spp1 were induced in neurons during moderate oxidative stress, suggesting that ROS-induced nuclear imports of HDAC4/5 promote deacetylation and activation of FOXOs. Transgenic flies expressing human HDAC5 or a constitutively nuclear HDAC5 mutant, raised on DEM food, displayed strong increases in Drosophila Gadd45 gene mRNA levels, and in silico approaches revealed Gadd45 as a putative FOXO target. Moreover, transgenic flies showed a possible translocation of expressed HDAC5-GFP to the nucleus of Drosophila neuronal cells. Therefore, the proposed mechanism occurring during low oxidative stress may be conserved and exploited therapeutically